Answer:
(a) View below.
(b) 104°
Explanation:
[a] Angle ∠4 is equal to the sum of the measures of the two nonadjacent interior angles because of the exterior angle theorem. This theorem is true because a triangle's angles add up to 180°, a straight line (in this case, line BCD) is equal to 180°. See attached for how this applies.
[b] As stated from part a, this angle is equal to the sum of the two opposite interior angles.
58° + 46° = 104°